class_docstr: Base class for TurntableCamera and ArcballCamera
docstr: The user-set distance. If None (default), the distance is
  internally calculated from the scale factor and fov.
docstr_tok: ["The","user-set","distance",".","If","None","(","default",")",",","the","distance","is","internally","calculated","from","the","scale","factor","and","fov","."]
code: def distance(self):
      """The user-set distance. If None (default), the distance is
      internally calculated from the scale factor and fov.
      """
      return self._distance
  
imports: from __future__ import division
  import math
  import numpy
  from .base_camera import BaseCamera
  from ...util import keys, transforms
  from ...visuals.transforms import MatrixTransform
label_desc: Use image node_id 2 for calling the Base3DRotationCamera obj's underlying member method code with example usage: obj.distance() and returns: self